superio/ite/common: Add temperature offset

Add a devicetree option to set temperature adjustment registers
required for thermal diode sensors and PECI. However, this commit does
not have the code needed to make PECI interface actually use these
registers. It only applies to diodes.

As a temporary workaround, one can set both THERMAL_DIODE and peci_tmpin
to the same TMPIN, e.g. TMPIN3.mode="THERMAL_DIODE" and peci_tmpin="3".
PECI, apparently, takes precedence over diode, so the adjustment register
will be set and PECI activated. Or simply use the followup patch, which
makes THERMAL_PECI a mode like THERMAL_DIODE.

I don't have hardware to test THERMAL_DIODE mode, but in case of PECI,
without this patch I had about -60°C on idle. Now, with offset 97,
which was taken from vendor bios, PECI readings became reasonable 35°C.

TEST=Set a temperature offset, then ensure that the value you set is
reflected in /sys/class/hwmon/hwmon*/temp[1-3]_offset

Change-Id: Ibce6809ca86b6c7c0c696676e309665fc57965d4
Signed-off-by: Vagiz Tarkhanov <rakkin@autistici.org>
Reviewed-on: https://review.coreboot.org/21843
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Nico Huber <nico.h@gmx.de>

3 files changed, 48 insertions, 11 deletions

diff --git a/src/superio/ite/common/env_ctrl.c b/src/superio/ite/common/env_ctrl.c
index 1e313ce715..c8274db6c8 100644
--- a/src/superio/ite/common/env_ctrl.c
+++ b/src/superio/ite/common/env_ctrl.c
@@ -99,13 +99,13 @@ static void enable_peci(const u16 base, const u8 tmpin)
  * into TMPINx register
  */
 static void enable_tmpin(const u16 base, const u8 tmpin,
-			 const enum ite_ec_thermal_mode mode)
+			 const struct ite_ec_thermal_config *const conf)
 {
 	u8 reg;
 
 	reg = ite_ec_read(base, ITE_EC_ADC_TEMP_CHANNEL_ENABLE);
 
-	switch (mode) {
+	switch (conf->mode) {
 	case THERMAL_DIODE:
 		reg |= ITE_EC_ADC_TEMP_DIODE_MODE(tmpin);
 		break;
@@ -115,12 +115,20 @@ static void enable_tmpin(const u16 base, const u8 tmpin,
 	default:
 		printk(BIOS_WARNING,
 		       "Unsupported thermal mode 0x%x on TMPIN%d\n",
-		       mode, tmpin);
+		       conf->mode, tmpin);
 		return;
 	}
 
 	ite_ec_write(base, ITE_EC_ADC_TEMP_CHANNEL_ENABLE, reg);
 
+	/* Set temperature offsets */
+	if (conf->mode != THERMAL_RESISTOR) {
+		reg = ite_ec_read(base, ITE_EC_BEEP_ENABLE);
+		reg |= ITE_EC_TEMP_ADJUST_WRITE_ENABLE;
+		ite_ec_write(base, ITE_EC_BEEP_ENABLE, reg);
+		ite_ec_write(base, ITE_EC_TEMP_ADJUST[tmpin-1], conf->offset);
+	}
+
 	/* Enable the startup of monitoring operation */
 	reg = ite_ec_read(base, ITE_EC_CONFIGURATION);
 	reg |= ITE_EC_CONFIGURATION_START;
@@ -233,7 +241,7 @@ void ite_ec_init(const u16 base, const struct ite_ec_config *const conf)
 
 	/* Enable HWM if configured */
 	for (i = 0; i < ITE_EC_TMPIN_CNT; ++i)
-		enable_tmpin(base, i + 1, conf->tmpin_mode[i]);
+		enable_tmpin(base, i + 1, &conf->tmpin[i]);
 
 	/* Enable reading of voltage pins */
 	ite_ec_write(base, ITE_EC_ADC_VOLTAGE_CHANNEL_ENABLE, conf->vin_mask);
diff --git a/src/superio/ite/common/env_ctrl.h b/src/superio/ite/common/env_ctrl.h
index fa131166c0..1be6436310 100644
--- a/src/superio/ite/common/env_ctrl.h
+++ b/src/superio/ite/common/env_ctrl.h
@@ -93,6 +93,26 @@
 #define   ITE_EC_ADC_TEMP_DIODE_MODE(x)		(1 << ((x)-1))
 #define ITE_EC_ADC_TEMP_EXTRA_CHANNEL_ENABLE	0x55
 
+/* Matches length of ITE_EC_TMPIN_CNT */
+static const u8 ITE_EC_TEMP_ADJUST[] = { 0x56, 0x57, 0x59 };
+
+#define ITE_EC_BEEP_ENABLE			0x5C
+#define   ITE_EC_TEMP_ADJUST_WRITE_ENABLE	(1 << 7)
+#define   ITE_EC_ADC_CLOCK_1MHZ			(6 << 4)
+#define   ITE_EC_ADC_CLOCK_2MHZ			(7 << 4)
+#define   ITE_EC_ADC_CLOCK_24MHZ		(5 << 4)
+#define   ITE_EC_ADC_CLOCK_31KHZ		(4 << 4)
+#define   ITE_EC_ADC_CLOCK_62KHZ		(3 << 4)
+#define   ITE_EC_ADC_CLOCK_125KHZ		(2 << 4)
+#define   ITE_EC_ADC_CLOCK_250KHZ		(1 << 4)
+#define   ITE_EC_ADC_CLOCK_500KHZ		(0 << 4)
+#define   ITE_EC_BEEP_ON_TMP_LIMIT		(1 << 2)
+#define   ITE_EC_BEEP_ON_VIN_LIMIT		(1 << 1)
+#define   ITE_EC_BEEP_ON_FAN_LIMIT		(1 << 0)
+#define ITE_EC_BEEP_FREQ_DIV_OF_FAN		0x5D
+#define ITE_EC_BEEP_FREQ_DIV_OF_VOLT		0x5E
+#define ITE_EC_BEEP_FREQ_DIV_OF_TEMP		0x5F
+
 #define ITE_EC_FAN_CTL_TEMP_LIMIT_OFF(x)	(0x60 + ((x)-1) * 8)
 #define ITE_EC_FAN_CTL_TEMP_LIMIT_START(x)	(0x61 + ((x)-1) * 8)
 #define ITE_EC_FAN_CTL_TEMP_LIMIT_FULL(x)	(0x62 + ((x)-1) * 8)
diff --git a/src/superio/ite/common/env_ctrl_chip.h b/src/superio/ite/common/env_ctrl_chip.h
index f01c574d47..8eb908e77a 100644
--- a/src/superio/ite/common/env_ctrl_chip.h
+++ b/src/superio/ite/common/env_ctrl_chip.h
@@ -28,6 +28,12 @@ enum ite_ec_thermal_mode {
 	THERMAL_RESISTOR,
 };
 
+struct ite_ec_thermal_config {
+	enum ite_ec_thermal_mode mode;
+	/* Offset is used for diode sensors and PECI */
+	u8 offset;
+};
+
 /* Bit mask for voltage pins VINx */
 enum ite_ec_voltage_pin {
 	VIN0 = 0x01,
@@ -74,25 +80,28 @@ struct ite_ec_config {
 	u8 peci_tmpin;
 
 	/*
-	 * Enable thermal mode on TMPINx.
+	 * Enable reading of voltage pins VINx.
 	 */
-	enum ite_ec_thermal_mode tmpin_mode[ITE_EC_TMPIN_CNT];
+	enum ite_ec_voltage_pin vin_mask;
 
 	/*
-	 * Enable reading of voltage pins VINx.
+	 * Enable temperature sensors in given mode.
 	 */
-	enum ite_ec_voltage_pin vin_mask;
+	struct ite_ec_thermal_config tmpin[ITE_EC_TMPIN_CNT];
 
 	/*
 	 * Enable a FAN in given mode.
 	 */
 	struct ite_ec_fan_config fan[ITE_EC_FAN_CNT];
+
+	/* FIXME: enable beep when exceeding TMPIN, VIN, FAN limits */
 };
 
 /* Some shorthands for device trees */
-#define TMPIN1	ec.tmpin_mode[0]
-#define TMPIN2	ec.tmpin_mode[1]
-#define TMPIN3	ec.tmpin_mode[2]
+#define TMPIN1	ec.tmpin[0]
+#define TMPIN2	ec.tmpin[1]
+#define TMPIN3	ec.tmpin[2]
+
 #define FAN1	ec.fan[0]
 #define FAN2	ec.fan[1]
 #define FAN3	ec.fan[2]